| 摘要 |
<p>In a scanning force microscope, a thin film of a magnetic material (46) is applied to the back surface of a force sensing cantilever (48). A small solenoid (62) is placed near the cantilever (48) so as to generate a field (B) normal to the soft axis of the cantilever (48). The field (B) is generated by an ac voltage source (66) and causes a time varying force to be applied to the cantilever (48). The corresponding modulation of a cantilever's position is sensed by reflection of a laser beam (58) into a position sensitive detector (60). The magnitude and phase of this signal are determined by a synchronous detector (68). Images of the sample surface (52) are made at constant force gradient by scanning the cantilever (48) over the surface (52) while adjusting the gap between the probe (64) and the sample (54) so as to maintain a constant output from the synchronous detector (68).</p> |
